Basin cover mounted to unequally-spaced anchor-retention areas

ABSTRACT

The basin cover having evenly-spaced covering elements mounted to shelf angles along the sides of the basin. These shelf angles are retained by anchor bolts to the inside edge of the rim of the basin. Flat tabs are adjustably spaced apart along the shelf angles and respectively overlap unevenly-spaced anchor retention areas of the basin. The flange portion of the shelf angles extend in a same plane as a walkway along the rim of the basin for widening this walkway. The new cover can be installed to basins of different conditions without major custom work.

TECHNICAL FIELD

The disclosure relates generally to covers for large open-top municipal and industrial reservoirs, and more particularly it pertains to symmetrical basin covers mountable to unequally-spaced anchor retention areas.

BACKGROUND OF THE ART

Covers for large municipal and industrial reservoirs or basins that are of interest herein are described and illustrated in the following documents:

-   U.S. Pat. No. 6,389,757 issued to C. DeGarie, on May 21, 2002; -   U.S. Pat. No. 6,612,079 issued to C. DeGarie et al., on Sep. 2,     2003; -   U.S. Pat. No. 8,555,556 issued to B. Howe, on Oct. 15, 2013.

The basins of interest herein are rectangular open-top municipal and industrial tanks, reservoirs or basins that are used for clarification of wastewater for example. Covers are used on these basins to reduce the ingress of rainwater and snow inside the basins; to block sunlight and control algae growth or to collect bio-gases released from the content of these basins. Covers for these basins are typically made of a flexible impermeable fabric sheet, stretched and supported on an array of spaced-apart arches. These arches are anchored to the rim of the basins. For aesthetic reasons and design considerations, these arches are evenly spaced and parallel to each other along the basin.

Some basins have narrow walkways there-around, and anchoring a new cover to these basins using traditional techniques reduces the width of these walkways to a dimension that is no longer acceptable by safety standards. In other examples, basins are often made of concrete, and the concrete of the walkways still contains embedded sockets, beam stubs and similar vestiges of an old cover. Because of these remains of an anterior construction, it becomes a challenge to support a new cover with precision and symmetry over such a basin. Improvement is desirable.

SUMMARY

In one aspect, the disclosure describes a basin that has unevenly-spaced anchor retention areas along the rim thereof and a cover than has evenly-spaced covering elements mounted to one or more shelf angle. The shelf angle is attached to the vertical portion of the rim of the basin. A series of flat tabs are affixed to the horizontal portion of the shelf angle. These flat tabs extend over the horizontal portion of the rim of the basin and are anchored to the horizontal portion of the rim of the basin. Each flat tab is positioned along the shelf angle in such a way as to overlap one of the unevenly-spaced anchor retention areas, and to be anchored to that anchor retention area. The cover can be installed to basins of different conditions without major custom work.

In another aspect, the disclosure describes a basin having a rim comprising opposite vertical edge surfaces and horizontal edge surfaces respectively contiguous with one of the vertical edge surfaces, and a cover mounted thereon. The cover comprises a plurality of spaced-apart arches mounted to a pair of shelf angles. These shelf angles are affixed to the rim of the basin. Each of the shelf angles has a web portion extending parallel with, and against one of the vertical edge surfaces of the rim of the basin, and a flange portion extending horizontally away from the vertical edge surface. The cover also has a plurality of flat tabs attached to the flange portion of the shelf angles at adjustably-spaced intervals. The flat tabs extend over the horizontal edge surfaces of the rim of the basin for retaining each shelf angle to the rim of the basin. The flat tabs retain the shelf angles and the arches of the cover to the rim of the basin. The shelf angles in cooperation with the flat tabs resist wind uplift forces and downward loading on the cover.

Although the rim of the basin may comprise limited anchor retention areas, the flat tabs are adjustable to overlap the anchor retention areas so that a standard cover can be mounted to a nonstandard basin.

The shelf angles are installed with the flange portion of the shelf angles extending in a same plane as the horizontal edge surfaces of the rim of the basin for widening this horizontal edge surfaces and create space for mounting the cover. When a walkway is associated with these horizontal edge surfaces, the shelf angles add to the width of this walkway, for widening this walkway.

Embodiments may include combinations of the above features.

This brief summary has been provided so that the nature of the invention may be understood quickly. Further details of these and other aspects of the subject matter of this application will be apparent from the detailed description included below and the drawings.

DESCRIPTION OF THE DRAWINGS

Reference is now made to the accompanying drawings, in which:

FIG. 1 is a perspective view of a basin cover according to the present invention;

FIG. 2 is a partial a cross-section view of the cover of FIG. 1;

FIG. 3 is an enlarged view of the cover-anchoring details as shown in detail circle 3 in FIG. 2;

FIG. 4 is a partial perspective view of the anchoring structure of the cover according to the preferred embodiment of the present invention;

FIG. 5 is a perspective plan view of a typical walkway bordering an old basin;

FIG. 6 is an alternate embodiment of the preferred anchoring structure illustrated in FIG. 3.

DETAILED DESCRIPTION

Aspects of various embodiments are described through reference to the drawings.

Referring firstly to FIGS. 1 and 2, there is disclosed therein a cover 20 according to the preferred embodiment of the present invention mounted to a rectangular basin. The cover 20 is made of spaced-apart arches 22 covered by a flexible impermeable sheet 24. The arches 22 are supported on the opposite longer sides of the basin. The basin of interest herein is made of concrete and has a concrete walkway 26 along the perimeter thereof. The preferred cover 20 also has handrails 28 there-around.

As can be appreciated from FIG. 1, the arches 22 are evenly spaced along the basin so that any wind uplift force or snow load on the cover is evenly supported. The arches 22 are also evenly spaced to accentuate a perception of quality and good engineering practices. Thirdly, the arches 22 are equally spaced to produce an esthetically appealing cover design.

The arches 22 are evenly spaced along a pair of supporting shelf angles 30 as can be seen in FIG. 3. Only one shelf angle is shown. The other side of the cover 20 is a mirror image. It will be appreciated that some installation may include only one shelf angle 30 along one side of a basin; the other side of the cover being affixed to the basin in a traditional manner.

The expression “shelf angle” is used herein to designate a structural angle that is mounted as a shelf to a vertical wall. The portion of that structural angle extending along the wall is referred to as the web portion, and the portion extending as a shelf is referred to as the flange portion, for convenience.

Referring now to FIGS. 2, 3 and 4 it will be appreciated that other elements of the preferred cover 20 are evenly spaced. A plurality of flexible sheet tighteners 32 are also evenly spaced along the shelf angle 30 in order to apply an even tension across the flexible sheet 24. Optionally, the upright posts 34 of the handrails 28 are also mounted to the shelf angle 30 and are equally spaced, for esthetic reasons.

The shelf angles 30 support the cover to the rim of the basin 20. Each shelf angle has a web portion 40 extending vertically along the vertical edge surface 42 of the basin, and a flange portion 44 extending in an overhang mode toward the center of the basin. The flange portion 44 is preferably mounted flush with the top surface of the walkway 26 so as to widen the existing walkway 26.

The cover 20 according to the preferred embodiment also has randomly spaced flat tabs 50 bolted to the shelf angle 30 and extending in opposite direction from the flange portion 44 of the shelf angle 30. In use, the tabs 50 extend over the walkway 26 and contribute to support the shelf angles 30 to the perimeter of the basin.

The tabs 50 are spaced apart unequal distances “A” and “B” as indicated in FIG. 4 to accommodate the availability of sound anchor retention areas along the perimeter of a basin. The main purpose of the flat tabs 50 is to provide horizontal resistance to the prying force caused by loads imposed on the flange portion 44 of the shelf angles 30. The flat tabs 50 prevent a twisting of the shelf angle 30 due to wind uplift forces for example.

Referring now to FIG. 5, the perimeter or walkway 26 of an old basin may include embedded beam stubs 60, sockets 62 from a previous handrail, grating 64 over a spillway, a pump 66; ducts, pipes, conduits, or other similar machinery. The perimeter of an old basin may also include deteriorated or disintegrating concrete spots 68 which would give little strength to an anchor bolt. Furthermore, the width “W” of a walkway 26 along an old basin may be too narrow to accommodate any kind of new fittings along its edges.

It will be appreciated that the sound concrete anchor retention areas 70 to which a cover may be anchored between the obstacles mentioned above are unevenly-spaced along the walkway 26. In order to overcome this inconvenience, the tabs 50 along the shelf angle 30 can be installed in an uneven spacings as required along the shelf angle 30 to correspond to the spacings “A” and “B” between the anchor retention areas 70 along the walkway 26. The flat tabs 50 are adjustably mountable along the shelf angle 30 by drilling holes through the flange portion 44 of the shelf angle 30 and bolting the tabs 50 to the flange portion.

Because of the shelf angles 30 and the adjustable tabs 50, it will be appreciated that a standard cover can be mounted to an old basin with limited custom work.

In the cover 20 according to the preferred embodiment, the flexible sheet 24 is tightened across the arches 22 by a series of tighteners 32 that are also mounted to the shelf angles 30 through bolts. These tighteners act on a pipe mounted in a hem along the bottom edge of the flexible sheet.

Referring now to FIG. 6, it will be appreciated that if sufficient space is available on the walkway 26, the handrail posts 34 may be anchored directly to the surface of the walkway 26, as illustrated. Also a gutter 80 may be installed along the shelf angle 30 to convey rainwater to the ends of the basin.

Again in FIG. 6, another advantage of the shelf angles 30 can be understood from the illustration. The shelf angles 30 can be pre-drilled at the manufacturing shop or drilled as required during installation to accommodate the spacing of the flat tabs 50 and the attachment of the arches 22 and sheet tighteners 32 thereto. The shelf angles 30 are also drilled as required during installation to accommodate a placement of the anchor bolts 82, 84, according to sound engineering practices. The flat tabs 50 are preferably pre-drilled before installation, with a hole at each end.

As can be understood, a first series of anchor bolts 82 are mounted at right angle with a second series of anchor bolts 84. The horizontal and vertical anchor bolts 82 and 84 preferably enclose a reinforcing bar 86, when a location of such bar is known.

Therefore the structure at both ends of the arches 22 are supported to the basin against horizontal and vertical stresses as well as against torsional moment along the shelf angles. Furthermore, the preferred shelf angle 30 may optionally have spaced-apart gussets 88 thereon to prevent a deflection in the shelf angle in use.

The above description is meant to be exemplary only, and one skilled in the relevant art will recognize, that changes may be made to the embodiments described without departing from the scope of the invention disclosed. The present disclosure may be embodied in other specific form without departing from the subject matter of the claims. The present disclosure is intended to cover and embrace all suitable changes in technology. Modifications which fall within the scope of the present invention will be apparent to those skilled in the art, in light of a review of this disclosure, and such modifications are intended to fall within the appended claims. Also, the scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole. 

1. A basin having a rim comprising a vertical edge surface, and a horizontal edge surface respectively contiguous with said vertical edge surface, and a cover mounted thereon; said cover comprising: a plurality of spaced-apart arches mounted to a shelf angle; said shelf angle being affixed to said vertical edge surface of said rim; said shelf angle having a web portion extending along said vertical edge surface, and a flange portion extending horizontally away from said vertical edge surface; said web portion being attached to said vertical edge surface; and a plurality of flat tabs attached to said flange portion at spaced intervals and extending over said horizontal edge surface, said flat tabs being attached to said horizontal edge surface for retaining said shelf angle to said rim, and for retaining said cover to said basin.
 2. The basin as claimed in claim 1, wherein said flange portion extend in a same plane as said horizontal edge surface.
 3. The basin as claimed in claim 1, wherein said arches are evenly spaced along said shelf angle, and said flat tabs are unevenly spaced along said shelf angle.
 4. The basin as claimed in claim 3, wherein said horizontal edge surface have unevenly-spaced anchor retention areas thereon, and said tabs are spaced to correspondingly overlap said unevenly-spaced anchor retention areas.
 5. The basin as claimed in claim 4, wherein said vertical edge surface and said horizontal edge surface are made of concrete and said web portion of said shelf angle and said flat tabs are attached to said anchor retention areas by anchor bolts.
 6. The basin as claimed in claim 5, further comprising handrail posts mounted to said shelf angle, and said handrail posts are evenly spaced along said shelf angle.
 7. A basin having a rim comprising opposite vertical edge surfaces, and horizontal edge surfaces respectively contiguous with one of said vertical edge surfaces, and a cover mounted thereon; said vertical edge surfaces and said horizontal edge surfaces comprising unevenly-spaced anchor retention areas there along; said cover comprising: a plurality of evenly spaced arches mounted to a pair of shelf angles; said shelf angles being affixed to said rim; each of said shelf angles having a web portion extending along one of said vertical edge surfaces and a flange portion extending horizontally away from said vertical edge surface, along a plane of one or said horizontal edge surfaces; and a plurality of flat tabs attached to said flange portions of said shelf angles and being correspondingly spaced to overlap said unevenly-spaced anchor retention areas.
 8. The basin as claimed in claim 7, wherein said vertical edge surfaces and said horizontal edge surfaces are made of concrete and said web portion of said shelf angle and said flat tabs are fastened to said anchor retention areas by anchor bolts.
 9. The basin as claimed in claim 7, further comprising rain gutters mounted over said flange portions of said shelf angles.
 10. The basin as claimed in claim 7, wherein said shelf angles having gussets there along.
 11. The basin as claimed in claim 7, wherein said flange portions extend in a same plane as said horizontal edge surfaces.
 12. A shelf angle assembly for supporting a cover to a rim of a basin; wherein said rim has contiguous vertical and horizontal edge surfaces; said shelf angle assembly comprising: a shelf angle having a web portion; a flange portion; a plurality of holes in said web portion for attachments of said web portion to said vertical edge surface; and a plurality of flat tabs mounted to said flange portion of said shelf angle for attachment of said flange portion to said horizontal edge surface.
 13. The shelf angle assembly as claimed in claim 12, wherein said plurality of flat tabs are universally spaced along said flange portion.
 14. The shelf angle assembly as claimed in claim 12, wherein said plurality of flat tabs are drilled with a hole at each end.
 15. A method for mounting a cover to a basin having narrow walkway there along, comprising: anchoring a shelf angle to a vertical edge of said walkway for widening said walkway; mounting said cover to a flange portion of said shelf angle, and anchoring a plurality of spaced-apart flat tabs to said flange portion and to a horizontal surface of said walkway.
 16. The method as claimed in claim 15, further including the step of unevenly spacing said flat tabs along said flange portion to overlap spaced anchor-retention areas along said walkway. 